JBA headers quality concerns/pre-installation questions

Hello guys,
I've researched this a ton on this and other forums but I thought I'd get one last opinion before I install.
I've purchased a set of JBA long tubes for my 2004 tundra. My driver's side manifold is leaking so I thought of it as an opportunity for upgrade. I had decided to buy the silver ceramic ones but I got lucky and the seller couldn't find his last set, so he called me and upgraded me free to the titanium ceramic. They look sweet!
Now I'm not asking about the basic installation process, as I like to consider myself a somewhat able backyard mechanic and already have a good idea on how to get them installed. I also will be buying some quality multi layered steel gaskets.
My question is in regards to some past forums questioning the quality of the headers. I know they are not top notch quality, but they are the best we've got.
Now, I can see the tubes are welded to the flange plate from the inside and not on the outside of the flange plate. There is a gap around the tubes and the flange plate on the outside, which makes me think that could be a spot to rust or leak. I've read this happening at least once on another forum.
Should I fill in that gap before I install them? Or do you think I'll be fine, and that one instance was just by chance?
Also, I do not have the air injector tubes on my headers or stock manifolds. There are weld spots blocking the air injection tubes on the inside of the JBA headers. Do those need to be ground down so they won't be a potential high spot and create a leak? There is no apparent hole on the outside of the flange indicating that the welds were to fill in a hole, so maybe they were made intentionally to block off someone on the cylinder head side? I'm a graduate student working full time so I don't have a lot of extra time to pull these back off again and reinstall if there was a leak, hence why I came to the experts for any last minute tips.
Any other advice or tricks would be appreciated.
Thanks again, I enjoy being a part of this community

 

@FrenchToasty
Was it you plug welding up your headers recently?

 

Yes, I had to enlarge the air injection block off nubs on the header flange. So far so good after 40-50 miles

 

I wouldn’t worry about the back sides getting filled in, and if you don’t have AIP system, I still wouldn’t touch those block weld pools. Get Remflex gaskets or something of the like, and you should seal up the head just fine

 

I wouldn't be welding on those mounting flanges. For one they appear coated, all of that would have to come off to weld, good luck getting in that crevice. Secondly, unless done with skill and caution, you could end up warping the flange from the heat and cause bigger issues. Headers 'gon rust. That's what they do. It's just surface rust when they do usually. Those look thoroughly coated. Should be fine.

 

I have those same headers and bolted them on just how they came. It’s been a few thousand miles with no issues. Do you plan to extend the o2 sensors or did you buy the extensions? Also note you do not have to remove a motor mount.

 

I am planning on getting some stock connectors off of the main harness and o2 sensor from the salvage yard to make my own custom extensions that are plug and play. I figured it would be better than cutting my 02 sensor harness up.
Thanks for the tip on the motor mount. Part of my vision was to loosen them and jack up that side of the engine to get a better angle at those two middle bolts, but I'll try without doing that first. A1auto has a good video replacing stock manifolds without taking off the motor mount so it obviously can be done. I'm also a little weary about loosening any bolts that don't need to be. I know every project is one broken bolt away from becoming a 3-4 day project, so if I don't need to loosen motor mounts, I'll try not to.

They are "titanium ceramic" coated, which I had hoped would prevent rust as long as possible. It's not a super heavy coating, as I easily scratched it with my knife getting the bubble wrap off of them, so it could be easily removed. But they do look good. I did think about warping the flange, but it is 1/2" thick so I figured going slow and allowing the metal to cool would prevent that. I'm not a professional welder, so I do probably lack the necessary skill and technique to do it, but I know I can tackle the rest of the exhaust! I'll leave them as they are.

10-4. I was thinking of some felpro MLS gaskets or Mahle, but Remflex gets mentioned a lot in these forums. I'll see if I can find some. I have two weeks until I get a break for a few days so there's still time to order stuff.

Thanks again guys. I'll be sure to post pictures once its done.

 

Remflex makes one that says it’s for 1 3/4 port that’s the one you want; they don’t list one specific for JBA long tubes but I know for a fact it fits perfectly

 

I don't think there is a benefit to welding the back side.